Question

HOMEWORK PROBLEM 1 The Grashof Criterion This problem concerns the classification of four-bar linkages. Link lengths: Lo, fixed link; Ly, driver crank; L2, coupler; L3, follower crank; L2 = 100 mm, 12 = 200 mm, 13 = 300 mm. Find the ranges of values for Lo, if the linkage can be classified as follows: a. Grashof mechanism b. Crank-rocker mechanism c. Drag link mechanism d. Double-rocker mechanism e. Change --point mechanism f. Triple-rocker mechanism

Answer 1

E Solution Given Link length Li = 100mm . L₂= 200mm L3 300mm Lo= a) Crrashof mechanism For grashof mechanism I min tlmost < Ptq For doing this assume Lo» lmax Imin > L, P- L₂ q - L3 Lit Lo < L₂+ L3 10o + Lo < 200 + 300 > > 100+ Lo <500 => Lok 400 6 crank-rocker mechanism Imin shortest lmin Li link 100 C Assume) Condition for crank rocker mechanism is shortest link adjust to the fixed link (given) ic fixed length be this need do be larger than L, R100 <Lo < 400 Lo

Drog Also called link mechonum crank cronk mechanism Condition for cronk crank mechanum is lmin boom Here fixed link gives as Low emin Lo is fixed Och Lo<10ommo stulov botasbit Slox d) Double rocker mechanism 52 is not In the mechanum double rocker by ir grashor's linkage posible By non- grashor's linkage boei so Imixt Imox > Ptq => L + Lo > LatL3 Lo > t '200+ 300 - 100 Wisk Lo> 400 naibula NO rocker To get double Lo >400 mechanism 399 co Gost loob